The present invention relates generally to installation of electric power cables and, more particularly, to methods and apparatus for installing overhead electric cables to a residential dwelling.
Electric power is often provided to residential dwellings by way of an overhead service cable connected between the dwelling and a service pole. Such service cables are typically comprised of a plurality of insulated wires wrapped around and supported by a bare base wire or cable. At the service pole, the base wire is often secured to an insulated spool mounted on a clevis extending from the upper portion of the pole. The insulated wires are, for example, connected to power carrying or "energized" wires in the pole, but since the weight of the service cable is carried by the base wire, the insulated wires are not under any substantial tension during normal connection.
The service cable is normally connected to the dwelling by one of two methods: an insulated anchor nob attached to a steel riser pipe or attached directly to the house. In either case, the base wire is secured to the nob and normally supports the weight of the service cable. Even where the base wire is not attached to the riser pipe, the insulated wires are frequently run through the riser pipe from the weatherhead down into the meter base for electrical connection with the internal residential wiring.
While such arrangements have been generally satisfactory, certain problems have arisen when the service cable has been subject to damage from high winds directly and/or impact with falling tree limbs and other obstructions. For example, when excessive tension is placed on the service cable, the house anchor nob can be pulled away from the house regardless of whether it is screwed into the house directly or attached to the riser pipe. In the latter case, the riser pipe can be pulled away as well. As a result, the roof, facia, and/or siding of the house as well as the meter base can be damaged. Since the utility company providing the electric service often disclaims responsibility for accidents past the weatherhead and this damage occurs directly "downstream" of the weatherhead, the repair expenses are frequently borne by the customer or owner of the residence.
Moreover, if the damage is extensive and a hazard exists due to the proximity of the insulated, current carrying or energized wires to areas where people and animals could come into contact with those wires, the utility company will typically shut off electric service until the customer has the repairs made. As a result of this sometimes extended service outage, the customer will typically incur secondary expenses incident to defrosted refrigerators and freezers (food spoilage) and/or sump pump failure (flooded basements and lower building levels).
Additionally, where the service cable has been subject to sufficient force to completely sever the connection to the house, the energized wires which have broken off from the house may present a fire and electrocution hazard on the ground if, as is often the case, there is still an electrical connection to the service pole wiring. When, for example, this occurs as a result of a nighttime storm, the hazard may not be quickly or easily detected. Thus, customers, passersby and utility repair persons may be placed in serious risk of injury.
Accordingly, it is an object of the present invention to provide an improved method and apparatus for connecting electric service cables to residential dwellings and other structures having like service connection formats. Other objects include the provision of:
A. an apparatus which minimizes the repair time and expenses associated with service cable disconnection, PA1 B. an apparatus which reduces the risk of injury incident to disconnected electric cables, PA1 C. an apparatus which permits reduced power outage time in the event of a service cable disconnection, PA1 D. a service cable connection arrangement which does not damage the dwelling to which it is attached when the cable is subject to excess tension, and PA1 E. a service cable connection arrangement which de-energizes when the cable is subject to excess tension.
These and other objects of the present invention are obtained by the provision of a breakaway connection arrangement for electric power lines having two retaining elements, each receiving an end of an electrically conductive wire for crimpable connection therewith, and being separably joined by a conductive element within an insulated housing or sheath. This type of connection is used at least at the service pole end of the service cable such that when a predetermined level of force or tension is applied to the service cable, the cable separates from the pole and the conductive wires are de-energized. The predetermined level of separation force is selected such that the service cable separates from the pole under less tension than would be required to pull the anchor nob and/or riser pipe from the house. This is accomplished by selection of the separation force needed to cause the conductive element to pull apart from one or both of the retaining elements. That selection is, for example, made by the choice of the crimping force applied to the initial assembly of the conductive element into the retaining elements.
Other objects, advantages and novel features of the present invention will now become readily apparent to those skilled in the art upon consideration of the drawings and detailed description below.